This invention relates to a process for removal of hydrogen fluoride contaminant from a mixture comprising gaseous hydrogen chloride. In accordance with another aspect, this invention relates to the removal of undesired hydrogen fluoride contaminant from a gaseous mixture comprising hydrogen chloride and sulfuryl fluoride.
It is known in the art that the hydrogen fluoride contaminant of a gaseous hydrogen chloride mixture can be removed therefrom by intimate contact with silica gel or a liquid composition consisting of water and sulfur trioxide. However, the resulting products, silicon tetrafluoride and chlorosulphonic acid, respectively, are volatile and pass out of the system with the hydrogen chloride, thus requiring additional expense for equipment and procedures to remove these by-products. See, for example, U.S. Pat. No. 3,074,779. Other prior art processes, for example, U.S. Pat. No. 3,140,916, require multiple step processes and equipment to achieve the removal of hydrogen fluoride.
The production of sulfuryl fluoride from gaseous mixtures of sulfur dioxide, chlorine and hydrogen fluoride (see U.S. Pat. Nos. 2,875,127 (use as a fumigant) and 2,772,144, 3,092,458 and 3,320,030 (processes) also has attendant problems of removing undesired excess hydrogen fluoride from product mixture containing sulfuryl fluoride. Such hydrogen fluoride apparently forms an azeotrope mixture with by-product hydrogen chloride and the azeotrope mixture cannot be successfully distilled and separated from the sulfuryl fluoride product. While the hydrogen fluoride contaminant can be removed according to prior art methods mentioned above, such methods suffer disadvantages in that additional equipment and procedures, etc., necessary to remove resulting hydrogen fluoride by-products or treat the same prior to waste disposal are encountered at additional expense.
Accordingly, an object of this invention is to provide a process for removing undesired hydrogen fluoride contaminant from gaseous mixtures comprising hydrogen chloride or sulfuryl fluoride and hydrogen chloride. Other objects and aspects, as well as the several advantages of the invention, will become apparent upon consideration of the accompanying disclosure and appended claims.